Debugging A Program - Casio FX-7400G User Manual

3. Debugging a Program

A problem in a program that keeps the program from running correctly is called a
"bug," and the process of eliminating such problems is called "debugging." Either of
the following symptoms indicates that your program contains bugs and that debug-
ging is required.
• Error messages appearing when the program is run
• Results that are not within your expectations
u u u u u To eliminate bugs that cause error messages
An error message, like the one shown below, appears whenever something illegal
occurs during program execution.
When such a message appears, press d or e to display the location where the
error was generated, along with the cursor. Check the "Error Message Table" for
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steps you should take to correct the situation.
u u u u u To eliminate bugs that cause bad results
If your program produces results that are not what you normally expect, check the
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tents" for details on how to change program contents.
4. Calculating the Number of Bytes Used
by a Program
This unit comes with 7 kbytes of memory. A byte is a unit of memory that can be
used for storage of data.
There are two types of commands: 1-byte commands and 2-byte commands.
• Examples of 1-byte commands: sin, cos, tan, log, (, ), A, B, C, 1, 2, etc.
• Examples of 2-byte commands: Lbl 1, Goto 2, etc.
While the cursor is located inside of a program, each press of d or e causes the
cursor to move one byte.
• You can check how much memory has been used and how much remains at any
time by selecting the MEM icon in the Main Menu and entering the MEM Mode.
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See "Memory Status (MEM)" for details.
Programming Chapter 8
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